Terminal silicone capped regiospecific glycerin polyesters

ABSTRACT

The present invention is directed to a series of glycerin based polymers that have been designed to have very specific substitution patterns, herein referred to as regiospecific substitution (RSS). The attachment of terminal mono-functional silicone polymers engineered polyesters of glycerin results in heretofore unrecognized products. The unique properties include lower surface tension, better spreadability and a dry skin feel, all of which cannot be attained without the use of a terminal silicone. Incorporation of silicone into the terminal position requires a very specific synthesis regime to establish the sought after regiospecificity.

RELATED APPLICATION

This application is a continuation in part of U.S. Ser. No. 13/373,974, filed Dec. 8, 2011.

FIELD OF THE INVENTION

The present invention is directed to a series of glycerin-based polymers that have been designed to have very specific substitution patterns, herein referred to as regio-specific substitution (RSS). The attachment of terminal mono-functional silicone polymers engineered polyesters of glycerin results in heretofore unrecognized products. The unique properties include lower surface tension, better spreadability and a dry skin feel, all of which cannot be attained without the use of a terminal silicone. Incorporation of silicone into the terminal position requires a very specific synthesis regime to establish the sought after regiospecificity.

Natural oils are triglycerides produced by plants and animals as a mechanism to store energy in the form of neutral fats. While being very successful as a store of energy for cells, these products are oily and do not possess the derived aesthetics for widespread use in cosmetics. The compounds of the present invention provide properties including skin feel and thermo-sensitive properties (i.e. alteration in properties as the temperature increases). The properties of the natural triglycerides are controlled by the fatty (alkyl) group contained therein and normally are predominantly oleyl groups (C18). Nature does not provide much of a variation in the groups. We have surprisingly found that by linking triglycerides into polymer backbones and capping the polymer with monofunctional silicone products, the performance and structure can de fine tuned. To improve the performance and properties of triglycerides, several silicone terminated polymeric triglyceride mimics were synthesized. The properties of these polymers can be controlled and tuned by judicial control of the polymerization conditions. Glycerin polyesters with different pendent alkyl groups with varying fatty chain length will provide a unique multi-dimensional polymer. This polymer will has “compartments” of solid and liquid pendant group domains if the proper pendant groups are chosen. This unique multi-dimensional, high definition polymer will have very unique physical properties, including unique shear and flow behaviors. These polymers will provide outstanding and unique skin feels when used in cosmetic applications.

These polymers have been designed to be “epigenomic friendly polymers”. By “epigenomic friendly polymers” is meant polymers that are designed to have the desired functionality regiospecifically located either within the polymer or at the external portions, and have molecular weights above 1,500 mwu (daltons) so as to minimize penetration into the skin. It is becoming better and better recognized that low molecular weight, non-polymeric products applied to the skin can penetrate and either up regulate or down regulate genes that can cause unintended consequences. An example is reported by deFlora et al in at http://www.ncbi.nlm.nih.gov/pubmed/21536718. It states “Among endocrine disruptors, the xenoestrogen bisphenol A (BPA) deserves particular attention due to widespread human exposure. Besides hormonal effects, BPA has been suspected to be involved in breast and prostate carcinogenesis, which share similar estrogen-related mechanisms”. There are numerous other examples of lower molecular weight non-proteins causing unintended consequences after penetrating the skin. “Epigenomic friendly polymers” are too large to penetrate.

BACKGROUND OF THE INVENTION

Triglycerides are common natural materials, their structure is:

Triglycerides are esters that are the reaction product of glycerin and fatty acids.

Triglycerides are very common in nature and are commonly used in cosmetic products to provide physical properties and ascetics. Triglycerides are commonly called oils, fats, butters and waxes. These terms are used to describe the physical and chemical composition of the triglyceride. Butters, oils and fats are all triglycerides. The major physical difference between butters, oils and fats are their melt and titer points: Fats have a titer point of over 40.5° C., oils have a titer point of below 40.5° C., and butters have a titer below 40.5° C. but above 20° C. Oils are liquid at room temperature and we now use this word to describe any compound that is a liquid and is insoluble in water. As a result, Jojoba is referred to as oil, despite the fact it is really a liquid wax.

Because oils, fats, butters and waxes are complex mixtures of homologues of similar chemical structures, it is difficult to obtain a true melting point. As the lower molecular weight fractions melt, they act as solvents to dissolve the higher molecular weight products. This results in a very wide melting “range” for these compounds. For this reason, titer point is generally determined on fats, oils, waxes and butters.

Titer is defined as the re-solidification point of the melted oil, fat butter or wax. The procedure is to heat the product to be tested until it is completely liquid, then to slowly cool with stirring. This is done until the temperature stays constant for 30 seconds, or begins to rise. The titer point is the highest temperature indicated by this rise.

Triglycerides are the tri-ester of glycerin with three equivalents of fatty acid. Fatty acids are defined as those acids having alkyl or alkylene groups being C-5 and higher. The reaction is as follows:

Triglycerides occur commonly in nature, but lack the desired aesthetics for many personal care applications. It is the pursuit of improving the feel of these commonly occurring natural triglycerides that are the materials of interest in the present invention.

U.S. Pat. No. 2,914,546 to Barsky et al teaches interesterification of mixed glyceryl compounds.

U.S. Pat. No. 6,306,906 to Wohlman and O'Lenick teach a process for conditioning hair and skin which comprise contacting the skin or hair with an effective conditioning concentration of a of the reaction product of meadowfoam oil and an ester selected from the group consisting of beeswax, jojoba oil, carnauba wax, and candelilla wax.

U.S. Pat. No. 6,180,668 to Wohlman and O'Lenick disclose a series of “reconstituted meadowfoam oils”, used on skin for moisturizing and emollient applications. The term reconstituted as used hereon refers to a process in which meadowfoam oil and one or more oils of natural origin are transesterified under conditions of high temperature and catalyst to make a “reconstituted product” having an altered alkyl distribution and consequently altered chemical and physical properties.

These referenced patents are incorporated herein by reference.

None of these patents provide polyester derivatives with regiospecific terminal silicone capping envisioned by the present invention. Specifically, they are not polymeric materials that have the benefit of unique physical properties due to molecular weight increase, no skin penetration due to high molecular weight, and the combination of terminal silicone and internal groups that can be liquid, solid or mixtures thereof.

Fatty acids of differing chain lengths and structures will have different physical properties. A triglyceride containing two different fatty chain length with have physical properties of a blend of the two fatty acids. If the fatty acids are confined to a domain of the polymer (pendant groups are located in regio-specific positions of the polymer backbone), a multi-domain polymer is formed. This multi-domain polymer will have highly organized “pockets” or domains of solid fatty groups, surrounded by liquid domains. The physical properties of the multi-domain polymer will be extremely different than the random triglyceride. By judicious control of the placement of these domains results in a high definition polymer. The preparation of polymers with highly desired aesthetics requires that different sections of the molecule have controlled alkyl groups. Addition of all the groups in the reaction mixture results in a random alkyl substitution pattern and loss of the desired aesthetics. Only by careful stepwise reaction can the products having exact structural properties be assured, thereby assuring performance in highly sophisticated formulations.

THE INVENTION Object of the Invention

The current invention is directed toward a silicone capped regiospecific polyesters that are synthesized from glycerin. These regiospecific polyesters will have very unique physical properties and have a wide variety of solubilities.

SUMMARY OF THE INVENTION

It has been discovered that not only the polymer make up, i.e. the monomers that make up the polymer backbone, but also the polymer design can be controlled and used as an efficient tool in tuning the ascetics and performance of a polymer. The polymers of the current invention are synthesized by a step growth polymerization, specifically a polycondensation polymerization. A simple example of a polycondensation polymerization is shown below:

In this simple example, the polymerization is the reaction between a di-acid and a di-alcohol. The polymerization is an equilibrium reaction that gives off water as a byproduct. The polymerization proceeds to high molecular weight by the removal of water as steam. It is common practice in polymer chemistry to actively control the molecular weight of the polymer by controllable techniques. One of these techniques is the use of mono-functional monomers during the polymerization process. Mono-functional monomers or so-called “chain terminators”, will react during the polymerization process like every other monomer. The major difference between a mono-functional monomer and a multifunctional monomer is that unlike a typical multifunctional monomer, a mono-functional monomer has only one reactive group. The moment that the mono-functional monomer reacts onto the polymer backbone the polymer chain loses the ability to continue to grow because it has no more react-able functional groups. The chain terminator reaction is as follows:

Chain terminators get their names because once they react, the polymerization stops so they are always on the end of the polymer chain.

We have found that by the use of mono-functional silicone monomers can be used to design a polymer that is regospecific, (also refereed to as regio-specific substitution (RSS)). Regiospecific refers to a polymer that has regions of different pendant groups. A polymer can be synthesized that has two or more regions by utilizing mono-functional monomers. The polymer chain ends are controlled by the use of mono-functional monomers, while the internal pendant groups can be reacted onto the polymer backbone by the use of a different fatty acid. The regions of the polymer are shown below:

As shown above, the polymer's pendant groups can be controllably placed into two different regions. These regions will then allow the polymer to act like a block copolymer. Regio-specific polymers will have drastically different properties, i.e. different melt point, crystallinity, and solubility than the same polymer made in a random approach.

This regiospecific polymer is obtained by the multi-step polymerization approach. In the first step a try functional alcohol is reacted with a di-acid and a mono-functional acid as shown below:

As seen above, the polymerization occurs as a typical polycondensation polymerization. The polymerization will proceed until one of the monomers is completely consumed. Once the polymerization has reached a desired chain length, the polymerization can be terminated by the addition of a “chain terminator”. Chain terminators are monofunctional monomers that will react onto the polymer chain end and prevent the polymer from growing. The chain terminator reaction is shown below.

As seen above, once the chain terminators react with the growing polymer chain, the chain loses the ability to continue to react.

This new technique provides a way to selectively add end groups onto the polymer chain ends. Since the chain terminators are held until the end of the polymerization, they are protected from trans-esterfication reaction with other alcohols involved in the polymerization process. The polymer produced is designed specifically to maximize the performance of the polymers. These polymers are classified as High Definition Polymers. The term “High Definition Polymers” refers to a class of polymers that have specific structures that affect the polymer performance. A glycerin polyester of the current invention that has both a solid and liquid pendant and terminal groups and will produce a High Definition Polymer that has structured liquid and solid domains.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the present invention is very specific silicone terminated glyceryl polyesters that fall into one of two categories.

(1) Silicone Terminated Glycerin Polyester

The polyester of the structure:

wherein,

-   -   R¹ is

-   -   a is an integer ranging from 1 to 20;     -   R³ is independently selected from the group consisting of alkyl         having 2 to 12 carbons, an alkyl conforming to the following         structures:

and mixtures thereof;

-   -   R⁴ is an alkyl containing 8 to 26 carbons or mixtures thereof;     -   n is an integer ranging from 5 to 15.

Preferred Embodiment

In a preferred embodiment a is 1.

In a more preferred embodiment a is 5.

In a more preferred embodiment a is 20.

In a more preferred embodiment R³ is dimer acid.

In a more preferred embodiment R⁴ is an alkyl having 18 carbons.

In a more preferred embodiment R³ is an alkyl having 7 carbons.

Another aspect of the present invention is a process for conditioning hair and skin that comprises contacting the hair or skin with an effective conditioning concentration of a very specific polyesters.

(2) Silicone/Alkyl Terminated Glycerin Copolyester

A glycerin copolyester conforming to the following structure:

wherein,

-   -   R¹ is

-   -   a is an integer ranging from 1 to 20;     -   R² is alkyl containing 2 to 26 carbons.     -   R³ is independently selected from the group consisting of alkyl         having 2 to 12 carbons, an alkyl conforming to the following         structures:

or mixtures thereof;

-   -   R⁴ is an alkyl containing 8 to 26 carbons or mixtures thereof;     -   n is an integer ranging from 5 to 15.

Preferred Embodiment

In a preferred embodiment a is 1.

In a more preferred embodiment a is 5.

In a more preferred embodiment a is 20.

In a more preferred embodiment R³ is dimer acid.

In a more preferred embodiment R⁴ is an alkyl having 18 carbons.

In a more preferred embodiment R³ is an alkyl having 7 carbons.

In a more preferred embodiment R² is an alkyl having 18 carbons.

Another aspect of the present invention is a process for conditioning hair and skin that comprises contacting the hair or skin with an effective conditioning concentration of a very specific polyesters.

(a) Glycerin Polyester

A process for conditioning hair and skin which comprises contacting the hair or skin with an effective conditioning concentration of a polyester conforming to the following structure:

wherein,

-   -   R¹ is an alkyl containing 8 to 26 carbons, or mixtures thereof;     -   R³ is

-   -   x is an integer ranging from 2 to 50;     -   R⁴ is an alkyl containing 8 to 26 carbons or mixtures thereof;     -   with the proviso that R¹ and R⁴ are different;     -   n is an integer ranging from 5 to 15.

Preferred Embodiment

In a preferred embodiment said effective conditioning concentration ranges from 0.1% to 45% by weight.

In a more preferred embodiment said effective conditioning concentration ranges from 1% to 20% by weight.

In a preferred embodiment R′ and R⁴ are different.

In a more preferred embodiment one of R¹ and R⁴ is solid and the other is liquid, (as used herein, liquid is meant pourable at 25° C., by solid is meant solid at 25° C.).

In a more preferred embodiment R¹ is an alkyl having 18 carbons.

In a more preferred embodiment x is 10.

In a more preferred embodiment R⁴ is an alkyl having 18 carbons.

In a more preferred embodiment x is 25.

(b) Glycerin Copolyester

A process for conditioning hair and skin which comprises contacting the hair or skin with an effective conditioning concentration of a polyester conforming to the following structure:

wherein,

-   -   R¹ is an alkyl containing 8 to 26 carbons or mixtures thereof;     -   R² is an alkyl containing 8 to 26 carbons or mixtures thereof;     -   R³ is

-   -   x is an integer ranging from 2 to 50;     -   R⁴ is an alkyl containing 8 to 26 carbons or mixtures thereof;     -   with the proviso that R′ and R⁴ are different;     -   n is an integer ranging from 5 to 15.

Preferred Embodiment

In a preferred embodiment said effective conditioning concentration ranges from 0.1% to 45% by weight.

In a more preferred embodiment said effective conditioning concentration ranges from 1% to 20% by weight.

In a preferred embodiment R′, R² and R⁴ are different.

In a more preferred embodiment one of R¹, R² and R⁴ is solid and the other two are liquid.

In a most preferred embodiment one of R¹ R² and R⁴ is liquid and the other two are solid.

In a more preferred embodiment R¹ is an alkyl having 18 carbons.

In a more preferred embodiment x is 10.

In a more preferred embodiment R⁴ is an alkyl having 18 carbons.

In a more preferred embodiment x is 25.

Process using Silicone Terminal Glycerin Polyester

The process for conditioning hair and skin which comprises contacting the hair or skin with an effective conditioning concentration of a polyester conforming to the following structure:

wherein;

-   -   R¹ is

-   -   a is an integer ranging from 1 to 20;     -   R³ is independently selected from the group consisting of alkyl         having 2 to 12 carbons, an alkyl conforming to the following         structures:

or mixtures thereof;

-   -   R⁴ is an alkyl containing 8 to 26 carbons or mixtures thereof;     -   n is an integer ranging from 5 to 15.

Preferred Embodiment

In a preferred embodiment said effective conditioning concentration ranges from 0.1% to 45% by weight.

In a more preferred embodiment said effective conditioning concentration ranges from 1% to 20% by weight.

In a preferred embodiment a is 1.

In a more preferred embodiment a is 5.

In a more preferred embodiment a is 15.

In a more preferred embodiment R³ is derived from dimer acid.

In a more preferred embodiment R⁴ is an alkyl having 18 carbons.

In a more preferred embodiment R³ is an alkyl having 7 carbons.

Raw Materials

Fatty Acids

Fatty acids useful in the practice of the present invention are items of commerce commercially available from Cognis.

Fatty acid Names

Fatty acids useful as raw materials in the preparation of compounds of the present invention are commercially available from a variety of sources including Procter and Gamble of Cincinnati Ohio. The structures are well known to those skilled in the art. R—C(O)—OH

Saturated Molecular Example R Formula Common Name Weight 1 C₇H₅ Caprylic 144 2 C₉H₁₉ Capric 172 3 C₁₁H₂₃ Lauric 200 4 C₁₃H₂₇ Myristic 228 5 C₁₄H₂₉ Pentadecanoic 242 6 C₁₅H₃₁ Palmitic 256 7 C₁₇H₃₅ Stearic 284 8 C₁₇H₃₅ Isosteric 284 9 C₁₉H₃₉ Arachidinic 312 10 C₂₁H₄₃ Behenic 340 12 C₂₆H₅₃ cetrotic 396 13 C₃₃H₆₇ geddic acid 508

Unsaturated Molecular Example R Formula Common Name Weight 14 C₁₇H₃₃ Oleic 282 15 C₁₇H₃₁ Linoleic 280 16 C₁₇H₂₉ Linolenic 278 17 C₁₅H₂₉ Palmitoleic 254 18 C₁₃H₂₅ Myristicoleic 226 19 C₂₁H₄₁ Erucic 338

Glycerin

Glycerin is an item of commerce and is available from a variety of sources including Cognis of Cincinnati Ohio. It conforms to the following structure:

Glycerin is propane-1,2,3-triol and has a CAS number of 56-81-5.

Dicarboxylic Acid

Dicarboxylic acid useful as raw materials in the synthesis of the compounds of the present invention are commercially available from a variety of sources including Cognis. They conforms to the following structure;

wherein;

-   -   c is an integer ranging from 1 to 10.

Saturated Dicarboxylic acids Molecular Example Common Name c Weight 20 Malonic 1 104 21 Succinic 2 118 22 Glutaric 3 132 23 Adipic 4 146 24 Pimelic 5 160 25 Subric 6 174 26 Azelaic 7 188 27 Sebacic 8 202 28 Undecanedioic 9 216 29 Dodecanedioic 10 230

Example 30

Dimer Acid

Dimer acid is an item of commerce available commercially from Cognis Corporation. It conforms to the following structure:

Example 31

Hydrogenated Dimer Acid

Hydrogenated dimer acid is an item of commerce available commercially from Henkel Corporation. It conforms to the following structure:

Silicone Capped Glycerin Chain Terminator

Glycerin fatty esters were prepared by SurfaTech Corporation, of Lawrenceville, Ga. They are prepared by the esterification of glycerin with monofunctional silicone carboxylates. They conform to the following structure:

wherein;

-   -   R¹ is

-   -   a is an integer ranging from 1 to 20.

They are made using silicone polymers available from Siltech LLC conforming to the following structure:

-   -   a is an integer ranging from 1 to 20;

These products are the result of hydrosilylation of a silanic hydrogen containing polymer with methyl undecylenate.

Silicone Capping Agents Molecular Glycerin Example “a” Value Weight Grams Grams 32 1 510.4 229.3 20.7 33 5 806.8 236.5 13.5 34 10 1177.3 240.6 9.4 35 20 1918.3 244.1 5.9

Silicone Glycerin Chain Terminator

Glycerin mixed alkyl fatty esters were prepared by SurfaTech Corporation, of Lawrenceville, Ga. They are prepared by the esterification of glycerin with two equivalents of monofunctional silicone compounds (examples 32-35). They conform to the following structure:

wherein;

-   -   R¹ is

-   -   a is an integer ranging from 1 to 20.     -   R² is an alkyl containing 8 to 26 carbons.

Monofunctional Alkyl Group Silicone (R¹) (R²) Glycerin Example Example Grams Example Grams Grams 36 32 208.9 1 22.7 18.3 37 33 203.4 7 35.2 11.4 38 34 215.9 8 25.8 8.3 39 35 227.9 14 16.6 5.4

General Procedure

A specified number of grams glycerin is added to a specified amount of monofunctional silicone undecylenate (examples 32-35). The reaction mixture is heated to 160-180° C. Methanol is removed by vacuum during the reaction process. The residual methyl ester will diminish as the reaction proceeds. The reaction is cooled once the residual methyl undecylenate to change over an additional two hours at elevated temperature. The product is used without purification.

Polymerization

A specified number of grams glycerin is added to a specified amount of fatty acids (examples 1-18) and diacids (examples 20-30) or dimer acid (example 31 & 32). The reaction mixture is heated to 160-180° C. Water is removed by vacuum during the reaction process. The reaction is monitored by the determination of acid value. The acid value will diminish as the reaction proceeds. Once the acid value reaches a desired value, a specified amount of chain terminator (examples 36-39) is added into the reaction flask. The reaction is cooled once the acid value fails to change over an additional two hours at elevated temperature. The product is used without purification.

Chain Terminator R⁴ Diacid Glycerin Example Example Grams Example Grams Example Grams Grams 40 32 130.8 2 50.5 21 41.6 27.1 41 33 97.1 7 81.0 23 45.7 26.2 42 34 154.8 8 45.0 26 35.7 14.6 43 35 104.6 10 45.3 30 87.9 12.3 44 32 72.2 14 45.7 31 117.1 14.9 End Cap End Cap (R¹) (R²) R⁴ Diacid Glycerin Example Example Grams Example Grams Example Grams Example Grams Grams 45 32 63.3 36 71.4 2 48.9 21 40.3 26.2 46 33 46.9 37 55.5 7 78.1 23 44.2 25.3 47 34 74.4 38 84.0 8 43.3 26 34.3 14.0 48 35 51.5 39 55.5 10 44.5 30 86.4 12.1 49 32 50.5 36 37.2 14 41.7 31 106.9 13.6

APPLICATIONS EXAMPLES

These polymers have a wide variety of applications including, but not limited to, the modification of physical properties. The use of a regiospecific silicone terminated glycerin polyester is a very efficient and attractive way to produce a product with a low surface tension, great spreadability, and luxurious feel. This effect is due to the molecular structure, specifically its regiospecificity wherein the silicone groups are terminal and the fatty groups are internal. While not wanting to be held to one specific reason for this, we believe that the terminal groups are what is dominant at the skin oil interface, providing silicone like feel and surface tension and the fatty groups being internal are effecting the solubility.

These glycerin polyesters' physical properties, including solid state and skin feel, can be selectively tuned by the selection of R⁴ groups. When the group is liquid a dry feeling liquid results. When the R⁴ group is solid a butter with outstanding spreadability is achieved. When the R⁴ group is a mixture of solid and liquid a thixotropic butter is achieved.

While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth hereinabove but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains. 

The invention claimed is:
 1. A polyester having the structure:

wherein, R¹ is;

a is an integer ranging from 1 to 20; R² is alkyl containing 2 to 26 carbon atoms; R³ is independently selected from the group consisting of alkyl having 2 to 12 carbon atoms, and an alkyl conforming to the following:

and mixtures thereof; R⁴ is an alkyl containing 8 to 26 carbon atoms or mixtures thereof; n is an integer ranging from 5 to
 15. 2. A polyester of claim 1 wherein a is
 1. 3. A polyester of claim 1 wherein a is
 5. 4. A polyester of claim 1 wherein a is
 20. 5. A polyester of claim 1 wherein R⁴ is an alkyl having 18 carbon atoms.
 6. A polyester of claim 1 wherein R³ is an alkyl having 7 carbon atoms.
 7. A polyester of claim 1 wherein R² is an alkyl having 18 carbon atoms. 